The present invention relates to a wireless communication device applicable to a wireless communication network, and more particularly to a microcomputer applied to a baseband part and the like of the wireless communication device. It relates to a technology effectively applied to Bluetooth communication devices forming, e.g., piconet.
Wireless communication devices such as Bluetooth communication devices, wireless LAN communication devices, and mobile communication devices have a radio frequency (RF) part for performing wireless communications and a baseband part for performing data processing. The RF part and the baseband part are not always operating. A mobile communication device disclosed in Japanese Unexamined Patent Publication No. 2000-244351, to reduce power consumption during intermittent receive waits, stops the oscillation operation of a high-accuracy clock generation circuit required for communications during a call wait, and resumes the oscillation operation by using a timing circuit operating on a clock signal of a low-frequency clock generation circuit of a clock circuit required to operate at all times. Also, a cellular phone disclosed in Japanese Unexamined Patent Publication No. Hei 10(1998)-215293 uses a circuit operating on an oscillation clock of a clock oscillator to resume the oscillation operation of an operation clock generation circuit of a CPU.